A Chechen commander known as Saifullah al Shishani is reported to have been killed during fighting in the Syrian city of Aleppo. Units from the Al Nusrah Front for the People of the Levant, al Qaeda’s official branch in Syria, and Ahrar al Sham, one of the larger units in the Islamic Front, are currently fighting Syrian forces in an effort to take control of a prison in Aleppo. The two jihadist groups teamed up in December in an effort to take the prison and an adjoining hospital.

Saifullah was previously a commander in the Muhajireen Army, which is led by Chechen commander Omar al Shishani (the Chechen) and who has sworn allegiance to the Islamic State of Iraq and the Sham. Last year, Saifullah and another Chechen commander split with Abu Omar and the ISIS.

“Saifullah al-Shishani defected with 400 of his men three months ago, followed by Sheikh Salah al-Shishani with 800 of his men,” Al Akhbar reported in early January.

Al Qaeda General Command disowned the ISIS earlier this week. The denunciation took place after months of infighting between the ISIS on one side and the Al Nusrah Front and the Islamic Front on the other, as well as a very public leadership dispute between the leader of the ISIS and Al Nusrah. Al Qaeda attempted to mediate the dispute, and the ISIS’s leader, Abu Bakr al Baghdadi, rebuffed the efforts.

Pro-al Qaeda clerics are now calling on members of the ISIS to defect. While the move has weakened the ISIS in Syria, jihadists such as Saifullah who have been or currently are abandoning the group are largely flocking to the Al Nusrah Front.

Bill Roggio is a Senior Fellow at the Foundation for Defense of Democracies and the Editor of The Long War Journal.